Selective deposition

ABSTRACT

Methods are provided for selectively depositing a surface of a substrate relative to a second, different surface. An exemplary deposition method can include selectively depositing a material, such as a material comprising nickel, nickel nitride, cobalt, iron, and/or titanium oxide on a first surface, such as a SiO 2  surface, relative to a second, different surface, such as a H-terminated surface, of the same substrate. Methods can include treating a surface of the substrate to provide H-terminations prior to deposition.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. ProvisionalApplication No. 62/111,508, filed Feb. 3, 2015, entitled “SELECTIVEDEPOSITION” the disclosure of which is incorporated herein by referencein its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present application relates to selective deposition on a firstsurface of a substrate relative to a second surface. In addition,further processing can be used to subsequently deposit a differentmaterial on the second surface relative to the first.

Description of the Related Art

Selective deposition processes are needed in the semiconductor industryfor making smaller and smaller structures.

Integrated circuits are currently manufactured by an elaborate processin which various layers of materials are sequentially constructed in apredetermined arrangement on a semiconductor substrate.

The predetermined arrangement of materials on a semiconductor substrateis often accomplished by deposition of a material over the entiresubstrate surface, followed by removal of the material frompredetermined areas of the substrate, such as by deposition of a masklayer and subsequent selective etching process.

In certain cases, the number of steps involved in manufacturing anintegrated surface on a substrate could be reduced by utilizing aselective deposition process, wherein a material is selectivelydeposited on a first surface relative to a second surface. It is wellknown that it is very difficult to achieve selective deposition by vapordeposition processes such as atomic layer deposition (ALD). Typically,long carbon chain self-assembled monolayers (SAMs) are used to guidefilm growth on selected surfaces.

SUMMARY OF THE INVENTION

In some aspects, deposition methods are provided. In some embodiments asubstrate may be provided comprising a first surface and a second,different surface. In some embodiments the first surface comprises atleast one AH_(x) termination, where A is one or more of N, O, or S and xis from 1 to 2, and the second surface is a H-terminated surface. Insome embodiments the substrate may be contacted with a first vapor phaseprecursor comprising Ni, Ti, Fe, or Co to thereby selectively deposit amaterial comprising Ni, Ti, Fe, or Co on the first surface of thesubstrate relative to the second surface of the same substrate. In someembodiments the selectively deposited material may comprise Ni or Co. Insome embodiments the deposition method may further comprise contactingthe substrate with a second vapor phase reactant. In some embodimentsthe second H-terminated surface may be formed by treating at least aportion of the substrate surface prior to depositing the thin film. Insome embodiments the second H-terminated surface may be formed bytreating at least a portion of the substrate surface with a HF etch. Insome embodiments the second H-terminated surface may be formed bytreating at least a portion of the substrate surface with a siliconcompound comprising ClSiH₃ or (R^(I)R^(II)N)SiH₃, where R^(I) and R^(II)are independently selected from C₁-C₄ alkyls, such as methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl. In some embodiments the firstsurface may comprise at least one OH-termination. In some embodimentsthe first surface may comprise SiO₂. In some embodiments the firstsurface may be a low-k insulator. In some embodiments the first surfacemay comprise silicon oxide, silicon nitride, silicon oxynitride,fluorinated silica glass, carbon doped silicon oxide, or anothermaterial comprising at least 50% silicon oxide. In some embodiments thesecond surface may comprise —SiH₃, —SiH₂, or —SiH surface terminations.In some embodiments the material comprising Ni, Ti, Fe, or Co may beselectively deposited on the first surface relative to the secondH-terminated surface with a selectivity of at least 90%. In someembodiments the deposition method may be an ALD or CVD process.

In some aspects methods of selectively depositing a material comprisingNi, Ti, Fe, or Co on a substrate are provided. In some embodiments asubstrate comprising a first surface comprising silicon oxide may beprovided. In some embodiments at least a portion of the first surfacemay be etched to thereby provide a second H-terminated surface. In someembodiments a material comprising Ni, Ti, Fe, or Co may be selectivelydeposited on the first silicon oxide surface relative to the secondH-terminated surface. In some embodiments selectively depositing amaterial comprising Ni, Ti, Fe, or Co comprises selectively depositinguntil a material comprising Ni, Ti, Fe, or Co of a desired thickness isformed. In some embodiments the method of selectively depositing amaterial comprising Ni, Ti, Fe, or Co may be an ALD or CVD process. Insome embodiments etching at least a portion of the first surface maycomprise exposing said portion of the first surface to HF. In someembodiments the material comprising Ni, Ti, Fe, or Co film may beselectively deposited on the first surface relative to the secondH-terminated surface with a selectivity of at least 90%.

In some aspects methods for selectively forming SiO₂ on a substrate areprovided. In some embodiments the methods may comprise selectivelydepositing a material comprising Ni, Ti, Fe, or Co on a first surface ofthe substrate relative to a second, different, H-terminated surface ofthe same substrate, wherein the first surface comprises at least anAH_(x) termination, where A is one or more of O, N and S and x is from 1to 2. SiO₂ may be selectively deposited on the second H-terminatedsurface of the substrate relative to the first surface of the samesubstrate. In some embodiments a method may comprise etching thesubstrate to remove the material comprising Ni, Ti, Fe, or Co from thesubstrate. In some embodiments etching the substrate may compriseexposing the substrate to at least one of HCl, HNO₃, or H₂SO₄:H₂O₂. Insome embodiments the first surface may comprise an OH-terminatedsurface. In some embodiments the first surface may comprise siliconoxide. In some embodiments the second surface may comprise —SiH, —SiH₂,or —SiH₃ surface terminations. In some embodiments SiO₂ may beselectively deposited on the second surface of the substrate relative tothe first surface by a PEALD or thermal ALD process.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood from the Detailed Descriptionand from the appended drawings, which are meant to illustrate and not tolimit the invention, and wherein:

FIG. 1 illustrates a deposition process flow for selectively depositinga material such as Ni metal, nickel nitride (NiN_(x)), cobalt, iron ortitanium oxide on a first surface of a substrate relative to a second,different surface of the same substrate;

FIG. 2 illustrates a deposition process flow for selectively depositingnickel on a first surface of a substrate relative to a second, differentsurface of the same substrate;

FIG. 3 illustrates a deposition process flow for selectively depositingnickel nitride (NiN_(x)) on a first surface of a substrate relative to asecond, different surface of the same substrate;

FIG. 4 illustrates a deposition process flow for selectively depositingcobalt on a first surface of a substrate relative to a second, differentsurface of the same substrate;

FIG. 5 illustrates a deposition process flow for selectively depositingiron on a first surface of a substrate relative to a second, differentsurface of the same substrate;

FIG. 6 illustrates a deposition process flow for selectively depositingtitanium oxide on a first surface of a substrate relative to a second,different surface of the same substrate;

FIG. 7 depicts an nickel film that was selectively deposited on a firstsurface of a first substrate relative to a second, different surface ofthe first substrate and a second substrate according to an exemplaryprocess as described herein.

DETAILED DESCRIPTION

In some situations it is desirable to selectively deposit a material onone surface of a substrate relative to a second, different surface ofthe same substrate. For example, selective deposition may be used toform capping layers, barrier layers, etch stop layers, sacrificialand/or protective layers or for sealing pores, such as in porous low kmaterials.

Using the processes described herein, in some embodiments a materialcomprising Ni, Ti, Fe, or Co, such as Ni metal, nickel nitride orNiN_(x), cobalt, iron or titanium oxide structures can selectively begrown on SiO₂ based surfaces, and other surfaces as described herein. Asused herein, nickel nitride or NiN_(x) refers to a material comprisingat least some Ni—N bonds.

In some embodiments, a first material, such as a material comprising Ni,Ti, Fe, or Co, such as nickel, nickel nitride or NiN_(x), cobalt, ironor titanium oxide film, may be deposited selectively on a first surfacerelative to a second, different surface. For example, a nickel, nickelnitride, cobalt, iron or titanium oxide film can be selectivelydeposited on a low-k insulator surface, for example an oxide or nitridesurface, such as a form of silicon oxide or silicon nitride, relative toa second surface, such as a H-terminated surface of the same substrate.

In some embodiments the first surface on which selective depositionoccurs comprises an AH_(x)-termination, where A is one or more of N, Oor S and x is from 1 to 2. In some embodiments the first surfacecomprises OH-terminations. In some embodiments the first surface is anNH_(x)-terminated surface such as a —NH or —NH₂ terminated surface. Insome embodiments the first surface is an SH_(x)-terminated surface.

In some embodiments the first surface is a dielectric surface, such as aSiO₂ surface or silicon oxynitride surface. In some embodiments thefirst surface may comprise silicon oxides, silicon nitrides, siliconoxynitrides, fluorinated silica glass (FSG), carbon doped silicon oxide(SiOC) and/or materials containing more than about 50% silicon oxide. Insome embodiments the first surface comprises OH-groups and may comprise,for example, an alumina (Al₂O₃) surface with —OH surface groups.

In some embodiments the second surface is a —SiH₃, —SiH₂, or —SiHsurface. In some embodiments the second surface is formed by etchingnative oxide of silicon and the second surface comprises Si—H bonds. Insome embodiments the second surface is a pure silicon surface.

In some embodiments one or more surfaces may be treated to enhance ordecrease deposition on the treated surface relative to a second,different surface. In some embodiments a first surface may be treated,or activated, in order to enhance deposition on the first surfacerelative to one or more different surfaces. In some embodiments aportion of a first surface may be treated, or deactivated, in order todecrease deposition on the treated portion of the first surface relativeto the untreated first surface in some embodiments a second surface maybe treated, or deactivated, in order to decrease deposition on thesecond surface relative to the first surface of the substrate. In someembodiments a first surface is treated to enhance deposition and asecond surface is treated to decrease deposition, thereby increasingselective deposition on the first surface relative to the secondsurface.

In some embodiments a material comprising Ni, Ti, Fe, or Co, such as anickel, nickel nitride (NiN_(x)), Co, Fe or titanium oxide layer isdeposited on a first surface as discussed above, for example a low-kinsulator surface, such as an oxide surface, relative to a secondH-terminated surface of the substrate, such as a second surfacecomprising —SiH₃, —SiH₂, or —SiH. In some embodiments the first surfaceis a SiO₂ surface of a substrate. The second surface may be treatedprior to or at the beginning of the material comprising Ni, Ti, Fe, orCo, such as nickel, nickel nitride (NiN_(x)), Co, Fe or titanium oxidedeposition process in order to decrease deposition on the second surfacerelative to the first surface by forming H-terminations on the secondsurface. That is, selective deposition on the first surface (e.g. SiO₂)may be increased relative to the treated, or deactivated, secondsurface.

In some embodiments a first substrate surface comprising a dielectricmaterial, such as SiO₂, another oxide, or another material as describedherein, is treated to deactivate, or decrease deposition of the materialcomprising Ni, Ti, Fe, or Co, on one or more portions of the substrate.For example, one or more portions of the first substrate surface may betreated to form a second H-terminated surface, such as a —SiH₃, —SiH₂,or —SiH terminated surface. In some embodiments the one or more portionsof the first surface are treated with HF to form a second H-terminatedsurface in those areas.

In some embodiments a portion of the first surface as described herein,such as a portion of a SiO₂ surface or other oxide surface isdeactivated by reacting that portion of the surface with a siliconcompound to form a second surface comprising —SiH₃, —SiH₂, or —SiHgroups. Such silicon compounds may comprise, for example, ClSiH₃ or(R^(I)R^(II)N) SiH₃.

Following treatment to form a second H-terminated surface, a materialcomprising Ni, Ti, Fe, or Co may be selectively deposited on theremaining first surface, such as a first oxide (e.g. SiO₂) surface,relative to the H-terminated second surface.

In some embodiments a deactivating treatment does not involve formationof a self-assembled monolayer (SAM). In some embodiments a deactivatingtreatment does not comprise treatment with an organic agent.

In some embodiments a portion of an H-terminated surface (e.g., a —SiH₃,—SiH₂, or —SiH terminated surface) may be treated to facilitateselective deposition of a material comprising Ni, Ti, Fe, or Co, such asnickel, nickel nitride (NiN_(x)), Co, Fe or titanium oxide film on thetreated portion of the surface relative to an untreated surface. Forexample, a portion of a H-terminated surface, such as an etched Sisurface (SiH_(x)) may be treated to provide a hydrophilicOH-terminations on the treated portion of the surface. The OH-terminatedsurface can be reactive with nickel, Co, Fe or titanium precursors, asdescribed herein. Thus, in some embodiments OH-terminations (or otherterminations as described herein) can be provided to enhance depositionof the material comprising Ni, Ti, Fe, or Co on an OH-terminated portionof the surface relative to a second, remaining H-terminated surface.

The first surface on which material is selectively deposited, such as aSiO₂, other oxide, or other material, surface as described herein, maycomprise hydroxyl, or OH-groups, which may have the effect of making thesurface hydrophilic. Such OH-group surface terminations can occurnaturally when the surface is exposed to ambient conditions, for examplean atmosphere comprising water. In some embodiments at least a portionof a substrate surface may be treated to provide a first hydrophilicOH-terminated surface. In some embodiments at least a portion of ahydrophilic OH-terminated surface may be treated to increase the amountof OH-groups on the surface. For example, the surface may be exposed toH₂O vapor in order to increase the number of OH-groups at the surface.In some embodiments at least a portion of a silicon substrate surface isexposed to air and/or moisture, for example an atmosphere comprisingwater, in order to provide a first hydrophilic surface that comprises atleast some OH-groups. In some embodiments a hydrophilic surface is nottreated prior to deposition.

In some embodiments at least a portion of an OH-terminated surface (orother first surface as described herein) can be treated to inhibitdeposition of a material comprising Ni, Ti, Fe, or Co, such as nickel,nickel nitride (NiN_(x)), Co, Fe or titanium oxide thereon. For example,at least a portion of a first OH-terminated surface may be contactedwith HF to provide H-terminations and thereby provide a secondH-terminated surface. In some embodiments a SiO₂ surface is etched withHF, for example 0.5% HF, to provide a SiH_(x) surface at the etchedportion of the SiO₂ surface. As mentioned above, a portion of a firstOH-surface can also be treated by reacting the first surface with asilicon compound to form Si—H groups on that portion of the firstsurface. Such silicon compounds may comprise, for example, ClSiH₃ or(R^(I)R^(II)N)SiH₃, wherein R^(I) and R^(II) can be independentlyselected C₁-C₅ alkyl groups. The conversion of an OH-terminated surface(or other first surface as described herein) to a H-terminated surfacecan inhibit deposition of a material comprising Ni, Ti, Fe, or Co, suchas nickel, nickel nitride, Co, Fe or titanium oxide on the treatedportion of the surface relative to a first surface, such as a SiO₂surface of the substrate (or other first surface as described herein).

In some embodiments a semiconductor substrate is provided that comprisesa dielectric such as SiO₂. A portion of the surface may be selectivelyetched by exposure to HF, for example 0.5% HF, thereby creating a firstsurface comprising SiO₂ and a second surface comprisinghydrogen-terminated silicon, such as a —SiH₃, —SiH₂, or —Si—H surface atthe etched portion of the first SiO₂ surface. A material comprising Ni,Ti, Fe, or Co, such as nickel, nickel nitride (NiN_(x)), Co, Fe ortitanium oxide film may then be selectively deposited on the firstsurface comprising SiO₂ relative to the second H-terminated surface.

In some embodiments a semiconductor substrate is provided that comprisesa dielectric such as SiO₂. A portion of the surface may be selectivelyexposed to a silicon compound, for example, ClSiH₃, (R^(I)R^(II)N)₂SiH₂,X_(y)SiH_(4-y), (R^(I)R^(II)N)SiH_(4-y), (R^(I)R^(II)N)SiH₃, or anothersilicon precursor as described herein, to form Si—H surface groups, suchas SiH_(x) groups, on that portion of the surface, thereby creating afirst surface comprising SiO₂ and a second surface comprisinghydrogen-terminated silicon, such as a —SiH_(x) surface. A materialcomprising Ni, Ti, Fe, or Co, such as nickel, nickel nitride (NiN_(x)),Co, Fe or titanium oxide film may then be selectively deposited on thefirst surface comprising SiO₂ relative to the second H-terminatedsurface.

In some embodiments the deposition process is a chemical vapordeposition (CVD) type process. In some embodiments the depositionprocess is an atomic layer deposition (ALD) type process. In someembodiments the deposition process is a pure ALD process in which eachsurface reaction is self-limiting. In some embodiments the depositionprocess is a vapor deposition process comprising one or more depositioncycles in which a substrate is alternately and sequentially contactedwith a first vapor phase reactant and a second vapor phase reactant.

In some embodiments a material comprising Ni, such as a Ni layer isselectively deposited on a first surface of a substrate as describedabove, such as a first SiO₂ surface of a substrate, relative to a secondH-terminated surface, such as a —SiH_(x) surface on the same substrate.

In some embodiments a material comprising Co, such as a Co layer isselectively deposited on a first surface of a substrate as describedabove, such as a first SiO₂ surface of a substrate, relative to a secondH-terminated surface, such as a —SiH₃, —SiH₂, or —SiH surface on thesame substrate.

In some embodiments a material comprising Fe, such as a Fe layer isselectively deposited on a first surface of a substrate as describedabove, such as a first SiO₂ surface of a substrate, relative to a secondH-terminated surface, such as a —SiH₃, —SiH₂, or —SiH surface on thesame substrate.

In some embodiments a material comprising Ni, such as a nickel nitride(NiN_(x)) layer is selectively deposited on a first surface of asubstrate as described above, such as a first SiO₂ surface of asubstrate, relative to a second H-terminated surface, such as a surfacecomprising —SiH₃, —SiH₂, or —SiH on the same substrate.

In some embodiments a material comprising Ti, such as a titanium oxidelayer is selectively deposited on a first surface of a substrate asdescribed above, such as a first SiO₂ surface of a substrate, relativeto a second H-terminated surface, such as a surface comprising —SiH₃,—SiH₂, or —SiH on the same substrate.

In some embodiments deposition on a first surface of a substrate asdescribed herein, such as a SiO₂ surface of the substrate, relative to asecond H-terminated surface of the substrate is at least about 90%selective, at least about 95% selective, at least about 96%, 97%, 98% or99% or greater selective. In some embodiments deposition only occurs onthe first surface and does not occur on the second surface. In someembodiments deposition on the first surface of the substrate relative tothe second surface of the substrate is at least about 70% selective, orat least about 80% selective, which may be selective enough for someparticular applications. In some embodiments deposition on the firstsurface of the substrate relative to the second surface of the substrateis at least about 50% selective, which may be selective enough for someparticular applications.

In some embodiments an etch step may be used subsequent to or in thecourse of deposition to remove material that is non-selectivelydeposited. Although the addition of an etch step would typically addcost and complexity to the process, in some situations it may becommercially desirable, for example if it is less expensive overall thanother options. In some embodiments an etch process may be a wet etchprocess or a dry etch process. In some embodiments a dry etch ispreferable.

In some embodiments deposition on a first surface of a substrate asdescribed herein, such as a first SiO₂ surface of a substrate, relativeto a second H-terminated surface of the substrate can be performed up toabout 500 deposition cycles before losing the selectivity, or up toabout 50 deposition cycles, or up to about 20 deposition cycles, or upto about 10 deposition cycles, or up to about 5 deposition cycles beforelosing selectivity. In some embodiments even deposition of 1 or 2 cyclesbefore losing selectivity can be useful.

Depending on the specific circumstances, a loss of selectivity may beconsidered to have occurred when deposition on the first surface of thesubstrate relative to the second surface of the substrate is less thanabout 50%, less than about 60%, less than about 70%, less than about80%, less than about 90% selective, less than about 95% selective, lessthan about 96%, 97%, 98% or 99% selective or greater.

In some embodiments deposition on the first surface, such as a firstSiO₂ surface of the substrate relative to the second H-terminatedsurface of the substrate can be performed up to a thickness of about 50nm before losing the selectivity, or up to about 10 nm, or up to about 5nm, or up to about 3 nm, or up to about 2 nm, or up to about 1 nm beforelosing selectivity. In some embodiments even deposition of up to 3 Å or5 Å before losing selectivity can be useful. Depending on the specificcircumstances, a loss of selectivity may be considered to have occurredwhen deposition on the first surface of the substrate relative to thesecond surface of the substrate is less than about 50% selective, lessthan about 60% selective, less than about 70%, less than about 80%, lessthan about 90% selective, less than about 95% selective, less than about96%, 97%, 98% or 99% selective or greater.

CVD Type Processes

In some embodiments CVD can be used to selectively deposit a materialscomprising Ni, Ti, Fe, or Co, such as nickel, nickel nitride (NiN_(x)),Co, Fe or titanium oxide on a first substrate surface as describedabove, such as a first —OH surface, for example a SiO₂ surface, relativeto a second H-terminated surface, such as a surface comprising —SiH₃,—SiH₂, or —SiH as described herein. In some embodiments a materialcomprising Ni, Ti, Fe, or Co, such as nickel, nickel nitride, Co or Feis selectively deposited by a pulsed CVD process in which multiplepulses of a nickel, nickel nitride, Co or Fe precursor or reactants areseparated by purge or removal steps in which reactant is removed fromthe substrate surface.

CVD type processes typically involve gas phase reactions between two ormore reactants. The reactants can be provided simultaneously to thereaction space or substrate. The substrate or reaction space can beheated to promote the reaction between the gaseous reactants. CVDdeposition occurs when the reactants are provided to the reaction spaceor substrate. In some embodiments the reactants are provided until athin film having a desired thickness is deposited. As mentioned above,in some embodiments cyclical CVD type processes can be used withmultiple cycles used to deposit a thin film having a desired thickness.In some embodiments one or more plasma reactants can be used in the CVDprocess.

In some embodiments an ALD-process can be modified to be a partial CVDprocesses. In some embodiments a partial CVD process can include atleast partial decomposition of one or more precursors. In someembodiments ALD processes can be modified to be a pulsed CVD processes.In some embodiments an ALD process is modified to use overlapping orpartially overlapping pulses of reactants. In some embodiments an ALDprocess is modified to use extremely short purge or removal times, suchas below 0.1 s (depending on the reactor). In some embodiments an ALDprocess is modified to use extremely long or continuous pulse times. Forexample, in some embodiments an ALD process is modified to use no purgeor removal at all after at least one pulse. In some embodiments no purgeis used after a metal reactant pulse. In some embodiments no purge isused after an oxygen reactant pulse. In some embodiments no purge isused after either a metal reactant pulse or an oxygen reactant pulse.

In some embodiments a single metal precursor is utilized. Thus, in someembodiments the process may not include contacting the substrate with avapor phase second reactant. In some embodiments a substrate is exposedto one precursor pulse, or sequential precursor pulses separate by aprecursor removal or purge step. For example, in some embodiments asubstrate may be continuously or intermittently contacted with a vaporphase metal precursor and not with a vapor phase second reactant.Although in some embodiments a substrate may be contact by anotherspecies that does not react, such as an inert purge gas or carrier gas,in addition to the vapor phase metal precursor. In some embodiments adeposition process may include only one metal precursor pulse. In someembodiments the substrate may be contacted with a vapor phase metalprecursor, excess metal precursor and reaction byproducts, if any, maybe removed from the substrate surface, and the substrate may again becontacted with a vapor phase metal precursor, for example in asequential pulse. In some embodiments the substrate may not contactedwith a second reactant. Although in some embodiments a substrate may becontacted by another species that does not react, such as an inert purgegas or carrier gas, in addition to the vapor phase metal precursor.

ALD Type Processes

ALD type processes are based on controlled, self-limiting surfacereactions of precursor chemicals. Gas phase reactions are avoided byalternately and sequentially contacting the substrate with the reactantsor precursors. Vapor phase reactants are separated from each other onthe substrate surface, for example, by removing excess reactants and/orreactant byproducts from the reaction chamber or substrate surfacebetween reactant pulses or by moving the substrate from one reactant toanother.

Briefly, a substrate comprising a first surface and second, differentsurface is heated to a suitable deposition temperature, generally atlowered pressure. Deposition temperatures are generally maintained belowthe thermal decomposition temperature of the reactants but at a highenough level to avoid condensation of reactants and to provide theactivation energy for the desired surface reactions. Of course, theappropriate temperature window for any given ALD reaction will dependupon the surface termination and reactant species involved.

Here, the temperature is preferably at or below about 500° C., morepreferably at or below about 400° C. and most preferably from about 100°C. to about 350° C. In some cases, for example in cases in which nickelbetadiketiminato compounds are used for deposition, a temperature fromabout 275° C. to about 325° C. may be selected.

The surface of the substrate may be contacted with a vapor phase firstreactant. Conditions are preferably selected such that no more thanabout one monolayer of the first reactant is adsorbed on the substratesurface in a self-limiting manner. The appropriate contacting times canbe readily determined by the skilled artisan based on the particularcircumstances.

In some embodiments excess first reactant and reaction byproducts, ifany, are removed from the substrate surface, such as by purging with aninert gas. Purging means that vapor phase precursors and/or vapor phasebyproducts are removed from the substrate surface such as by evacuatinga chamber with a vacuum pump and/or by replacing the gas inside areactor with an inert gas such as argon or nitrogen. Typical purgingtimes are from about 0.05 to 20 seconds, more preferably between about 1and 10, and still more preferably between about 1 and 2 seconds.However, other purge times can be utilized if necessary, such as wherehighly conformal step coverage over extremely high aspect ratiostructures or other structures with complex surface morphology isneeded. In some embodiments the substrate is removed from a reactionspace comprising the first reactant.

The surface of the substrate is contacted with a vapor phase secondgaseous reactant. Excess second reactant and gaseous byproducts of thesurface reaction, if any, are removed from the substrate surface. Insome embodiments this may be accomplished by purging. In someembodiments the substrate is removed from the reaction space comprisingthe second reactant.

The steps of contacting and removing are repeated until a thin film ofthe desired thickness has been selectively formed on the first surfaceof substrate, with each cycle leaving no more than a molecularmonolayer. Additional phases comprising alternately and sequentiallycontacting the surface of a substrate with additional, differentreactants can be included to form more complicated materials, such asternary materials.

An excess of reactants or precursors is typically supplied in each phaseto saturate the susceptible structure surfaces. Surface saturationensures reactant occupation of all available reactive sites (subject,for example, to physical size or “steric hindrance” restraints) and thusensures excellent step coverage. Typically, less than one molecularlayer of material is deposited with each cycle, however, in someembodiments more than one molecular layer is deposited during the cycle.

Removing excess reactants or precursors can include evacuating some ofthe contents of a reaction space and/or purging a reaction space withhelium, nitrogen or another inert gas. In some embodiments purging cancomprise turning off the flow of the reactive gas while continuing toflow an inert carrier gas to the reaction space.

The precursors employed in the ALD type processes may be solid, liquidor gaseous materials under standard conditions (room temperature andatmospheric pressure), provided that the precursors are in vapor phasebefore they are contacted with the substrate surface. Contacting asubstrate surface with a vaporized precursor means that the precursorvapor is in contact with the substrate surface for a limited period oftime. Typically, the contacting time is from about 0.05 to 10 seconds.However, depending on the substrate type and its surface area, thecontacting time may be even higher than 10 seconds. Contacting times canbe on the order of minutes in some cases. The optimum contacting timecan be determined by the skilled artisan based on the particularcircumstances.

The mass flow rate of the precursors can also be determined by theskilled artisan. In some embodiments the flow rate of metal precursorsis preferably between about 1 and 1000 sccm without limitation, morepreferably between about 100 and 500 sccm.

The pressure in a reaction chamber is typically from about 0.01 to about20 mbar, more preferably from about 1 to about 10 mbar. However, in somecases the pressure will be higher or lower than this range, as can bedetermined by the skilled artisan given the particular circumstances.

Before starting the deposition of the film, the substrate is typicallyheated to a suitable growth temperature. The growth temperature variesdepending on the type of thin film formed, physical properties of theprecursors, etc. The growth temperatures are discussed in greater detailherein in reference to each type of thin film formed. The growthtemperature can be less than the crystallization temperature for thedeposited materials such that an amorphous thin film is formed or it canbe above the crystallization temperature such that a crystalline thinfilm is formed. The preferred deposition temperature may vary dependingon a number of factors such as, and without limitation, the reactantprecursors, the pressure, flow rate, the arrangement of the reactor,crystallization temperature of the deposited thin film, and thecomposition of the substrate including the nature of the material to bedeposited on. The specific growth temperature may be selected by theskilled artisan.

Examples of suitable reactors that may be used include commerciallyavailable equipment such as the F-120® reactor, F-450® reactor, Pulsar®reactors—such as the Pulsar® 2000 and the Pulsar® 3000-EmerALD® reactorand Advance® 400 Series reactors, available from ASM America, Inc. ofPhoenix, Ariz. and ASM Europe B. V., Almere, Netherlands. Othercommercially available reactors include those from ASM Japan K. K(Tokyo, Japan) under the tradename Eagle® XP and XP8.

In some embodiments a batch reactor may be used. Suitable batch reactorsinclude, but are not limited to, reactors commercially available fromand ASM Europe B. V (Almere, Netherlands) under the trade names ALDA400™and A412™. In some embodiments a vertical batch reactor is utilized inwhich the boat rotates during processing, such as the A412™. Thus, insome embodiments the wafers rotate during processing. In someembodiments in which a batch reactor is used, wafer-to-wafer uniformityis less than 3% (1 sigma), less than 2%, less than 1% or even less than0.5%.

The growth processes can optionally be carried out in a reactor orreaction space connected to a cluster tool. In a cluster tool, becauseeach reaction space is dedicated to one type of process, the temperatureof the reaction space in each module can be kept constant, whichimproves the throughput compared to a reactor in which is the substrateis heated up to the process temperature before each run.

A stand-alone reactor can be equipped with a load-lock. In that case, itis not necessary to cool down the reaction space between each run.

Referring to FIG. 1 and according to some embodiments a substratecomprising a first surface as described above, such as SiO₂, is providedat step 110. A portion of the oxide surface is selectively treated toform a surface comprising H-terminations 120. For example, the portionof the surface may be selectively etched such as with HF to form aH-terminated surface comprising —SiH₃, —SiH₂, or —SiH.

A materials comprising Ni, Ti, Fe, or Co, such as nickel, nickel nitride(NiN_(x)), Co, Fe or titanium oxide is selectively deposited on thefirst SiO₂ surface of the substrate relative to the second H-terminatedsurface by an ALD type deposition process 100 comprising multiplecycles, each cycle comprising:

contacting the surface of a substrate with a vaporized first precursorat step 130. The first precursor may comprise a nickel precursor, Coprecursor, Fe precursor or a titanium precursor;

removing excess first precursor and reaction by products, if any, fromthe surface at step 140;

contacting the surface of the substrate with a second vaporized reactantat step 150;

removing from the surface, at step 160, excess second reactant and anygaseous by-products formed in the reaction between the first precursorlayer on the first surface of the substrate and the second reactant,and;

optionally repeating at step 170 the contacting and removing steps untila thin film comprising the selectively deposited material of the desiredthickness has been formed.

As mentioned above, in some embodiments one or more surfaces of thesubstrate may be treated in order to enhance deposition on one surfacerelative to one or more different surfaces prior to beginning thedeposition process 100. In FIG. 1 this is indicated by step 120.

Although the illustrated deposition cycle begins with contacting thesurface of the substrate with the first precursor, in other embodimentsthe deposition cycle begins with contacting the surface of the substratewith the second reactant. It will be understood by the skilled artisanthat in general contacting the substrate surface with the firstprecursor and second reactant are interchangeable in the ALD cycle.

In some embodiments, the reactants and reaction by-products can beremoved from the substrate surface by stopping the flow of firstprecursor while continuing the flow of an inert carrier gas such asnitrogen or argon.

In some embodiments, the reactants and reaction by-products can beremoved from the substrate surface by stopping the flow of secondreactant while continuing the flow of an inert carrier gas. In someembodiments the substrate is moved such that different reactantsalternately and sequentially contact the surface of the substrate in adesired sequence for a desired time. In some embodiments the removingsteps, 140 and 160 are not performed. In some embodiments no reactantmay be removed from the various parts of a chamber. In some embodimentsthe substrate is moved from a part of the chamber containing a firstprecursor to another part of the chamber containing the second reactant.In some embodiments the substrate is moved from a first reaction chamberto a second, different reaction chamber.

In some embodiments each reaction is self-limiting and monolayer bymonolayer growth is achieved. These may be referred to as “true ALD”reactions. In some such embodiments the nickel precursor (or otherprecursor as described herein) may adsorb on the substrate surface in aself-limiting manner. A second reactant in turn will react with theadsorbed nickel precursor to form up to a monolayer of nickel (or othermaterial as described herein) on the substrate.

However, in some embodiments ALD-type reactions are provided, in whichthere may be some precursor decomposition, but the growth saturates.That is, in some embodiments although a certain amount of film growthmay be caused by thermal decomposition of the nickel precursor (or othermetal precursor as described herein) at some deposition temperatures,saturated growth is preferably achieved when the second reactant isutilized. Such a reaction is an example of an ALD-type reaction. In suchALD-type reactions, films with good uniformity and relatively fewimpurities can be deposited.

In some embodiments thermal decomposition of one or more precursorsoccurs, in particular the nickel, Co, Fe or Ti precursor. In such cases,the growth rate may not fully plateau with increasing pulse times.Rather, the growth rate may continue to rise with increased pulse times,although the growth rate may increase more slowly with ever increasingpulse times. Thus in some embodiments a pulsed-CVD type depositionprocess is used, in which reactants are provided alternately andseparately, but some gas-phase reactions may occur. Preferably theconditions are selected such that surface controlled decomposition isthe mechanism for decomposition, which leads to good uniformity and goodstep coverage. Reaction conditions can also be selected such that goodcontrol of the reactions is maintained, leading to good quality filmswith low impurities.

Thus, in some embodiments the deposition temperature is below thethermal decomposition temperature of the nickel precursor (or otherprecursor as described herein) while in other embodiments the depositiontemperature may be at or above the thermal decomposition temperature.

As mentioned above, in some embodiments a thin film is selectivelydeposited on a first surface, such as a SiO₂ surface relative to asecond H-terminated surface, such as a —SiH₃, —SiH₂, or —SiH terminatedsurface, by a pulsed CVD process in which a vapor phase metal precursoris intermittently pulsed into a reaction space comprising the substrateand purged from the reaction space. In some embodiments a single metalprecursor is utilized. In some embodiments a substrate is exposed to oneprecursor pulse, or sequential precursor pulses separated by a precursorremoval or purge step. Thus, in some embodiments the process may notinclude contacting the substrate with a vapor phase second reactant. Forexample, in some embodiments a substrate may be continuously orintermittently contacted with a vapor phase metal precursor and not witha vapor phase second reactant. Although in some embodiments a substratemay be contact by another species that does not react, such as an inertpurge gas or carrier gas, in addition to the vapor phase metalprecursor. In some embodiments a deposition process may include only onemetal precursor pulse. In some embodiments the substrate may becontacted with a vapor phase metal precursor, excess metal precursor andreaction byproducts, if any, may be removed from the substrate surface,and the substrate may again be contacted with a vapor phase metalprecursor, for example in a sequential pulse. In some embodiments thesubstrate may not contacted with a second reactant. Although in someembodiments a substrate may be contacted by another species that doesnot react, such as an inert purge gas or carrier gas, in addition to thevapor phase metal precursor.

Selective Deposition of Ni on SiO₂

As mentioned above, in some embodiments a material comprising nickel isselectively deposited on a first substrate surface (as described above,such as a SiO₂ surface of a substrate) relative to a second,H-terminated surface of the same substrate, such as an —SiH₃, —SiH₂, or—SiH surface.

In some embodiments the second, H-terminated surface is formed prior todeposition by treating a surface to provide H-terminations and therebyinhibit nickel deposition on the second surface relative to the firstsurface. In some embodiments the treatment may be an in situ treatment.In some embodiments the second surface may be an SiO₂ surface that istreated to provide a H-terminated surface, for example an —SiH₃, —SiH₂,or —SiH terminated surface. In some embodiments the second surface maybe contacted with a chemical that provides an H-termination, such as byforming a —SiH₃, —SiH₂, or —SiH surface. In some embodiments treatmentof a SiO₂ surface may comprise etching that surface with HF, such as0.5% HF. A mask or other processes may be used to treat one or moreportions of the first surface to create the second H-terminated surface.For example, a mask or other process may be used to selectively etch oneor more portions of a SiO₂ substrate in order to form a second SiH_(x)surface while remaining portions of the first SiO₂ surface are notdisturbed.

In some embodiments the first surface can be treated to enhance Nideposition thereon. For example, a first SiO₂ surface can be treated toincrease the amount of OH-groups on the surface.

In some embodiments nickel deposition on a first surface relative to asecond surface, such as a first SiO₂ surface of the substrate relativeto a second SiH_(x) surface of the substrate, is at least about 90%selective, at least about 95% selective, at least about 96%, 97%, 98% or99% or greater selective. In some embodiments deposition only occurs onthe first surface and does not occur on the second surface. In someembodiments deposition on the first surface of the substrate relative tothe second surface of the substrate is at least about 50% selective, atleast about 70% selective, or at least about 80% selective, which may beselective enough for some particular applications.

Referring to FIG. 2 and according to some embodiments a substratecomprising a first surface as described above, such as a SiO₂ surface isprovided at step 210. A portion of the SiO₂ surface is selectivelytreated by exposure to HF to form a H-terminated second surface, such asa —SiH₃, —SiH₂, or —SiH surface 220.

A material comprising nickel is selectively deposited 230 on the SiO₂surface of the substrate relative to the H-terminated surface by a vapordeposition process, such as by ALD or CVD.

In some embodiments an elemental Ni thin film is selectively formed on afirst SiO₂ surface of a substrate in a reaction chamber relative to asecond H-terminated surface, such as a —SiH₃, —SiH₂, or —SiH surface, byan ALD type process comprising multiple Ni deposition cycles, eachdeposition cycle comprising:

-   -   contacting the substrate surface with a first vapor phase        reactant comprising a first Ni precursor to form a layer of the        Ni precursor on the substrate;    -   removing excess first reactant from the substrate surface;    -   contacting the substrate with a second vapor phase reactant such        that the second reactant reacts with the first Ni precursor on        the substrate in a self-limiting manner to form Ni; and    -   removing excess second reactant and reaction byproducts, if any,        from the substrate surface.

This can be referred to as the Ni deposition cycle. Each Ni depositioncycle typically forms at most about one monolayer of Ni selectively onthe SiO₂ surface. In some cases where the deposition temperature isabove the decomposition temperature of the Ni precursor, more than onemonolayer of Ni can be formed in each Ni deposition cycle. The Nideposition cycle can be repeated until a film of a desired thickness isformed.

Although the illustrated Ni deposition cycle begins with provision ofthe first Ni precursor, in other embodiments the deposition cycle beginswith the provision of the second reactant. It will be understood by theskilled artisan that provision of the first Ni precursor and secondreactant are interchangeable in the ALD cycle.

In some embodiments, the reactants and reaction by-products can beremoved from the substrate surface by stopping the flow of reactantwhile continuing the flow of an inert carrier gas such as nitrogen orargon. In some embodiments the reactants and reaction by-products can beremoved from the substrate surface by removing the substrate from thereaction chamber, or moving the substrate within the reaction chamber.

As mentioned above, in some embodiments a nickel thin film isselectively deposited on a first surface, such as a SiO₂ surfacerelative to a second H-terminated surface, such as a —SiH₃, —SiH₂, or—SiH terminated surface, by a pulsed CVD process in which a vapor phasenickel precursor is alternately pulsed into a reaction space comprisingthe substrate and purged from the reaction space.

In some embodiments a single nickel precursor is utilized. Thus, in someembodiments the process may not include contacting the substrate with avapor phase second reactant. In some embodiments a substrate is exposedto one precursor pulse, or sequential precursor pulses separate by aprecursor removal or purge step. For example, in some embodiments asubstrate may be continuously or intermittently contacted with a vaporphase nickel precursor and not with a vapor phase second reactant.Although in some embodiments a substrate may be contact by anotherspecies that does not react, such as an inert purge gas or carrier gas,in addition to the vapor phase nickel precursor. In some embodiments adeposition process may include only one nickel precursor pulse. In someembodiments the substrate may be contacted with a vapor phase nickelprecursor, excess nickel precursor and reaction byproducts, if any, maybe removed from the substrate surface, and the substrate may again becontacted with a vapor phase nickel precursor, for example in asequential pulse. In some embodiments the substrate may not contactedwith a second reactant. Although in some embodiments a substrate may becontacted by another species that does not react, such as an inert purgegas or carrier gas, in addition to the vapor phase nickel precursor.

Selective Deposition of NiN_(x) on SiO₂

As mentioned above, in some embodiments a material comprising Ni, suchas a material comprising nickel nitride (NiN_(x)) is selectivelydeposited on a first substrate surface as described above, such as afirst SiO₂ surface of a substrate, relative to a second, H-terminatedsurface of the same substrate, such as an —SiH₃, —SiH₂, or —SiH surface.

In some embodiments the second, H-terminated surface is formed prior todeposition by treating a surface to provide H-terminations and therebyinhibit deposition of a material comprising Ni, such as a nickel nitrideon the second surface relative to the first surface. In some embodimentsthe treatment may be an in situ treatment. In some embodiments thesecond surface may be an SiO₂ surface that is treated to provide aH-terminated surface, for example an —SiH₃, —SiH₂, or —SiH terminatedsurface. In some embodiments the second surface may be contacted with achemical that provides an H-termination, such as by forming a —SiH₃,—SiH₂, or —SiH surface. In some embodiments treatment of a SiO₂ surfacemay comprise etching that surface with HF, such as 0.5% HF. A mask orother processes may be used to treat one or more portions of the firstsurface to create the second H-terminated surface. For example, a maskor other process may be used to selectively etch one or more portions ofa SiO₂ substrate in order to form a second SiH_(x) surface whileremaining portions of the first SiO₂ surface are not disturbed.

In some embodiments the first surface can be treated to enhancedeposition of a material comprising Ni, such as nickel nitride thereon.For example, a first SiO₂ surface can be treated to increase the amountof OH-groups on the surface.

In some embodiments NiN_(x) deposition on the first surface, such as afirst SiO₂ surface of the substrate, relative to the second H-terminatedsurface of the substrate is at least about 90% selective, at least about95% selective, at least about 96%, 97%, 98% or 99% or greater selective.In some embodiments NiN_(x) deposition only occurs on the first surfaceand does not occur on the second surface. In some embodiments NiN_(x)deposition on the first surface of the substrate relative to the secondsurface of the substrate is at least about 50% selective, at least about70% selective, or at least about 80% selective, which may be selectiveenough for some particular applications.

Referring to FIG. 3 and according to some embodiments a substratecomprising a surface as described above, such as a SiO₂ surface isprovided at step 310. A portion of the SiO₂ surface is selectivelytreated by exposure to HF to form a second surface comprisingH-terminations, such as —SiH₃, —SiH₂, or —SiH 320.

A material comprising Ni, such as Nickel nitride (NiN_(x)) isselectively deposited 330 on the SiO₂ surface of the substrate relativeto the H-terminated surface by a vapor deposition process, such as byALD or CVD.

In some embodiments a material comprising Ni, such as a nickel nitridethin film is selectively formed on a first SiO₂ surface on a substratein a reaction chamber relative to a second H-terminated surface, such asa SiH_(x) terminated surface, by an ALD type process comprising multiplenickel nitride deposition cycles, each deposition cycle comprising:

-   -   contacting the substrate surface with a first vapor phase        reactant comprising a first Ni precursor to form a layer of the        Ni precursor on the substrate;    -   removing excess first reactant from the substrate surface;    -   contacting the substrate with a second vapor phase nitrogen        reactant such that the second reactant reacts with the first Ni        precursor on the substrate in a self-limiting manner to form a        material comprising Ni, such as NiN_(x); and    -   removing excess second reactant and reaction byproducts, if any,        from the substrate surface.

This can be referred to as the NiN_(x) deposition cycle. Each NiN_(x)deposition cycle typically forms at most about one monolayer of NiN_(x)selectively on the SiO₂ surface. In some cases where the depositiontemperature is above the decomposition temperature of the Ni precursor,more than one monolayer of NiN_(x) can be formed in each NiN_(x)deposition cycle. The NiN_(x) deposition cycle is repeated until a filmof a desired thickness is formed.

In some embodiments, the reactants and reaction by-products can beremoved from the substrate surface by stopping the flow of reactantwhile continuing the flow of an inert carrier gas such as nitrogen orargon. In some embodiments the reactants and reaction by-products can beremoved from the substrate surface by removing the substrate from thereaction chamber, or moving the substrate within the reaction chamber.

As mentioned above, in some embodiments a NiN_(x) layer is selectivelydeposited on a first surface as described above, such as a SiO₂ surfaceof a substrate relative to a second H-terminated surface by a CVDprocess, such as a pulsed CVD process, in which a Ni precursor and anitrogen precursor are provided to the reaction chamber.

In some embodiments a single nickel precursor is utilized. Thus, in someembodiments the process may not include contacting the substrate with avapor phase second reactant. In some embodiments a substrate is exposedto one precursor pulse, or sequential precursor pulses separate by aprecursor removal or purge step. For example, in some embodiments asubstrate may be continuously or intermittently contacted with a vaporphase nickel precursor and not with a vapor phase second reactant.Although in some embodiments a substrate may be contact by anotherspecies that does not react, such as an inert purge gas or carrier gas,in addition to the vapor phase nickel precursor. In some embodiments adeposition process may include only one nickel precursor pulse. In someembodiments the substrate may be contacted with a vapor phase nickelprecursor, excess nickel precursor and reaction byproducts, if any, maybe removed from the substrate surface, and the substrate may again becontacted with a vapor phase nickel precursor, for example in asequential pulse. In some embodiments the substrate may not contactedwith a second reactant. Although in some embodiments a substrate may becontacted by another species that does not react, such as an inert purgegas or carrier gas, in addition to the vapor phase nickel precursor.

Selective Deposition of Co on SiO₂

As mentioned above, in some embodiments a material comprising cobalt isselectively deposited on a first substrate surface (as described above,such as a SiO₂ surface of a substrate) relative to a second,H-terminated surface of the same substrate, such as an —SiH₃, —SiH₂, or—SiH surface.

In some embodiments the second, H-terminated surface is formed prior todeposition by treating a surface to provide H-terminations and therebyinhibit cobalt deposition on the second surface relative to the firstsurface. In some embodiments the treatment may be an in situ treatment.In some embodiments the second surface may be an SiO₂ surface that istreated to provide a H-terminated surface, for example an —SiH₃, —SiH₂,or —SiH terminated surface. In some embodiments the second surface maybe contacted with a chemical that provides an H-termination, such as byforming a —SiH₃, —SiH₂, or —SiH surface. In some embodiments treatmentof a SiO₂ surface may comprise etching that surface with HF, such as0.5% HF. A mask or other processes may be used to treat one or moreportions of the first surface to create the second H-terminated surface.For example, a mask or other process may be used to selectively etch oneor more portions of a SiO₂ substrate in order to form a second SiH_(x)surface while remaining portions of the first SiO₂ surface are notdisturbed.

In some embodiments the first surface can be treated to enhance Codeposition thereon. For example, a first SiO₂ surface can be treated toincrease the amount of OH-groups on the surface.

In some embodiments cobalt deposition on a first surface relative to asecond surface, such as a first SiO₂ surface of the substrate relativeto a second SiH_(x) surface of the substrate, is at least about 90%selective, at least about 95% selective, at least about 96%, 97%, 98% or99% or greater selective. In some embodiments deposition only occurs onthe first surface and does not occur on the second surface. In someembodiments deposition on the first surface of the substrate relative tothe second surface of the substrate is at least about 50% selective, atleast about 70% selective, or at least about 80% selective, which may beselective enough for some particular applications.

Referring to FIG. 4 and according to some embodiments a substratecomprising a first surface as described above, such as a SiO₂ surface isprovided at step 410. A portion of the SiO₂ surface is selectivelytreated by exposure to HF to form a H-terminated second surface, such asa —SiH₃, —SiH₂, or —SiH surface 420.

Cobalt is selectively deposited 430 on the SiO₂ surface of the substraterelative to the H-terminated surface by a vapor deposition process, suchas by ALD or CVD.

In some embodiments an elemental Co thin film is selectively formed on afirst SiO₂ surface of a substrate in a reaction chamber relative to asecond H-terminated surface, such as a —SiH₃, —SiH₂, or —SiH terminatedsurface, by an ALD type process comprising multiple Co depositioncycles, each deposition cycle comprising:

-   -   contacting the substrate surface with a first vapor phase        reactant comprising a first Co precursor to form a layer of the        Co precursor on the substrate;    -   removing excess first reactant from the substrate surface;    -   contacting the substrate with a second vapor phase reactant such        that the second reactant reacts with the first Co precursor on        the substrate in a self-limiting manner to form Co; and    -   removing excess second reactant and reaction byproducts, if any,        from the substrate surface.

This can be referred to as the Co deposition cycle. Each Co depositioncycle typically forms at most about one monolayer of Co selectively onthe SiO₂ surface. In some cases where the deposition temperature isabove the decomposition temperature of the Co precursor, more than onemonolayer of Co can be formed in each Co deposition cycle. The Codeposition cycle is repeated until a film of a desired thickness isformed.

Although the illustrated Co deposition cycle begins with provision ofthe first Co precursor, in other embodiments the deposition cycle beginswith the provision of the second reactant. It will be understood by theskilled artisan that provision of the first Co precursor and secondreactant are interchangeable in the ALD cycle.

In some embodiments, the reactants and reaction by-products can beremoved from the substrate surface by stopping the flow of reactantwhile continuing the flow of an inert carrier gas such as nitrogen orargon. In some embodiments the reactants and reaction by-products can beremoved from the substrate surface by removing the substrate from thereaction chamber, or moving the substrate within the reaction chamber.

As mentioned above, in some embodiments a cobalt thin film isselectively deposited on a first surface, such as a SiO₂ surfacerelative to a H-terminated surface, such as —SiH₃, —SiH₂, or —SiHterminated surface, by a pulsed CVD process in which a vapor phasecobalt precursor is alternately pulsed into a reaction space comprisingthe substrate and purged from the reaction space.

In some embodiments a single cobalt precursor is utilized. Thus, in someembodiments the process may not include contacting the substrate with avapor phase second reactant. In some embodiments a substrate is exposedto one precursor pulse, or sequential precursor pulses separate by aprecursor removal or purge step. For example, in some embodiments asubstrate may be continuously or intermittently contacted with a vaporphase cobalt precursor and not with a vapor phase second reactant.Although in some embodiments a substrate may be contacted by anotherspecies that does not react, such as an inert purge gas or carrier gas,in addition to the vapor phase cobalt precursor. In some embodiments adeposition process may include only one cobalt precursor pulse. In someembodiments the substrate may be contacted with a vapor phase cobaltprecursor, excess cobalt precursor and reaction byproducts, if any, maybe removed from the substrate surface, and the substrate may again becontacted with a vapor phase cobalt precursor, for example in asequential pulse. In some embodiments the substrate may not contactedwith a second reactant. Although in some embodiments a substrate may becontact by another species that does not react, such as an inert purgegas or carrier gas, in addition to the vapor phase cobalt precursor.

Selective Deposition of Fe on SiO₂

As mentioned above, in some embodiments a material comprising Fe isselectively deposited on a first substrate surface (as described above,such as a SiO₂ surface of a substrate) relative to a second,H-terminated surface of the same substrate, such as an —SiH₃, —SiH₂, or—SiH surface.

In some embodiments the second, H-terminated surface is formed prior todeposition by treating a surface to provide H-terminations and therebyinhibit iron deposition on the second surface relative to the firstsurface. In some embodiments the treatment may be an in situ treatment.In some embodiments the second surface may be an SiO₂ surface that istreated to provide a H-terminated surface, for example an —SiH₃, —SiH₂,or —SiH surface. In some embodiments the second surface may be contactedwith a chemical that provides an H-termination, such as by forming a—SiH₃, —SiH₂, or —SiH surface. In some embodiments treatment of a SiO₂surface may comprise etching that surface with HF, such as 0.5% HF. Amask or other processes may be used to treat one or more portions of thefirst surface to create the second H-terminated surface. For example, amask or other process may be used to selectively etch one or moreportions of a SiO₂ substrate in order to form a second SiH_(x) surfacewhile remaining portions of the first SiO₂ surface are not disturbed.

In some embodiments the first surface can be treated to enhance Fedeposition thereon. For example, a first SiO₂ surface can be treated toincrease the amount of OH-groups on the surface.

In some embodiments nickel deposition on a first surface relative to asecond surface, such as a first SiO₂ surface of the substrate relativeto a second SiH_(x) surface of the substrate, is at least about 90%selective, at least about 95% selective, at least about 96%, 97%, 98% or99% or greater selective. In some embodiments deposition only occurs onthe first surface and does not occur on the second surface. In someembodiments deposition on the first surface of the substrate relative tothe second surface of the substrate is at least about 50% selective, atleast about 70% selective, or at least about 80% selective, which may beselective enough for some particular applications.

Referring to FIG. 5 and according to some embodiments a substratecomprising a first surface as described above, such as a SiO₂ surface isprovided at step 510. A portion of the SiO₂ surface is selectivelytreated by exposure to HF to form a H-terminated second surface, such asa —SiH₃, —SiH₂, or —SiH surface 520.

Fe is selectively deposited 530 on the SiO₂ surface of the substraterelative to the H-terminated surface by a vapor deposition process, suchas by ALD or CVD.

In some embodiments an elemental Fe thin film is selectively formed on afirst SiO₂ surface of a substrate in a reaction chamber relative to asecond H-terminated surface, such as a —SiH₃, —SiH₂, or —SiH surface, byan ALD type process comprising multiple Fe deposition cycles, eachdeposition cycle comprising:

-   -   contacting the substrate surface with a first vapor phase        reactant comprising a first Fe precursor to form a layer of the        Fe precursor on the substrate;    -   removing excess first reactant from the substrate surface;    -   contacting the substrate with a second vapor phase reactant such        that the second reactant reacts with the first Fe precursor on        the substrate in a self-limiting manner to form Fe; and    -   removing excess second reactant and reaction byproducts, if any,        from the substrate surface.

This can be referred to as the Fe deposition cycle. Each Fe depositioncycle typically forms at most about one monolayer of Fe selectively onthe SiO₂ surface. In some cases where the deposition temperature isabove the decomposition temperature of the Fe precursor, more than onemonolayer of Fe can be formed in each Fe deposition cycle. The Fedeposition cycle is repeated until a film of a desired thickness isformed.

Although the illustrated Fe deposition cycle begins with provision ofthe first Fe precursor, in other embodiments the deposition cycle beginswith the provision of the second reactant. It will be understood by theskilled artisan that provision of the first Fe precursor and secondreactant are interchangeable in the ALD cycle.

In some embodiments, the reactants and reaction by-products can beremoved from the substrate surface by stopping the flow of reactantwhile continuing the flow of an inert carrier gas such as nitrogen orargon. In some embodiments the reactants and reaction by-products can beremoved from the substrate surface by removing the substrate from thereaction chamber, or moving the substrate within the reaction chamber.

As mentioned above, in some embodiments a Fe thin film is selectivelydeposited on a first surface, such as a SiO₂ surface relative to aH-terminated surface, such as —SiH₃, —SiH₂, or —SiH, by a pulsed CVDprocess in which a vapor phase Fe precursor is alternately pulsed into areaction space comprising the substrate and purged from the reactionspace.

In some embodiments a single Fe precursor is utilized. Thus, in someembodiments the process may not include contacting the substrate with avapor phase second reactant. In some embodiments a substrate is exposedto one precursor pulse, or sequential precursor pulses separate by aprecursor removal or purge step. For example, in some embodiments asubstrate may be continuously or intermittently contacted with a vaporphase Fe precursor and not with a vapor phase second reactant. Althoughin some embodiments a substrate may be contact by another species thatdoes not react, such as an inert purge gas or carrier gas, in additionto the vapor phase Fe precursor. In some embodiments a depositionprocess may include only one Fe precursor pulse. In some embodiments thesubstrate may be contacted with a vapor phase Fe precursor, excess Feprecursor and reaction byproducts, if any, may be removed from thesubstrate surface, and the substrate may again be contacted with a vaporphase Fe precursor, for example in a sequential pulse. In someembodiments the substrate may not contacted with a second reactant.Although in some embodiments a substrate may be contacted by anotherspecies that does not react, such as an inert purge gas or carrier gas,in addition to the vapor phase Fe precursor.

Selective Deposition of TiO₂ on SiO₂

As mentioned above, in some embodiments a material comprising Ti, suchas TiO₂ is selectively deposited on a first substrate surface asdescribed above, such as a first SiO₂ surface of a substrate relative toa second, H-terminated surface of the same substrate.

In some embodiments the second, H-terminated surface is formed prior todeposition by treating a surface to provide H-termination and therebyinhibit deposition of a material comprising Ti, such as titanium oxidedeposition on the second surface relative to the first surface. In someembodiments the treatment may be an in situ treatment. In someembodiments the second surface may be an SiO₂ surface that is treated toprovide a H-terminated surface, for example an —SiH₃, —SiH₂, or —SiHsurface. In some embodiments the second surface may be contacted with achemical that provides an H-termination, such as by forming a —SiH₃,—SiH₂, or —SiH surface. In some embodiments treatment of a SiO₂ surfacemay comprise etching that surface with HF, such as 0.5% HF. A mask orother processes may be used to treat one or more portions of the firstsurface to create the second H-terminated surface. For example, a maskor other process may be used to selectively etch one or more portions ofa SiO₂ substrate in order to form a second —SiH₃, —SiH₂, or —SiH surfacewhile remaining portions of the first SiO₂ surface are not disturbed.

In some embodiments the SiO₂ surface can be treated to increase theamount of OH-groups on the surface.

In some embodiments deposition of a material comprising Ti, such as TiO₂on the first surface, such as a SiO₂ surface of the substrate relativeto the second H-terminated surface, such as a —SiH₃, —SiH₂, or —SiHsurface of the substrate is at least about 90% selective, at least about95% selective, at least about 96%, 97%, 98% or 99% or greater selective.In some embodiments TiO₂ deposition only occurs on the first surface anddoes not occur on the second surface. In some embodiments TiO₂deposition on the first surface of the substrate relative to the secondsurface of the substrate is at least about 50% selective, at least about70% selective, or at least about 80% selective, which may be selectiveenough for some particular applications.

Referring to FIG. 6 and according to some embodiments a substratecomprising a SiO₂ surface is provided at step 610. A portion of the SiO₂surface is selectively treated by exposure to HF to form a SiH_(x)surface comprising H-terminations 420.

Titanium oxide is selectively deposited 430 on the SiO₂ surface of thesubstrate relative to the H-terminated surface by a vapor depositionprocess, such as by ALD or CVD.

In some embodiments a material comprising Ti, such as a titanium oxidethin film is selectively formed on a first SiO₂ surface on a substratein a reaction chamber relative to a second H-terminated surface, such asa SiH_(x) surface, by an ALD type process comprising multiple titaniumoxide deposition cycles, each deposition cycle comprising:

-   -   contacting the substrate surface with a first vapor phase        reactant comprising a first Ti precursor to form a layer of the        Ti precursor on the substrate;    -   removing excess first reactant from the substrate surface;    -   contacting the substrate with a second vapor phase oxygen        reactant such that the second reactant reacts with the first Ti        precursor on the substrate in a self-limiting manner to form        TiO₂; and    -   removing excess second reactant and reaction byproducts, if any,        from the substrate surface.

This can be referred to as the TiO₂ deposition cycle. Each TiO₂deposition cycle typically forms at most about one monolayer of TiO₂selectively on the SiO₂ surface. In some cases where the depositiontemperature is above the decomposition temperature of the Ti precursor,more than one monolayer of TiO₂ can be formed in each TiO₂ depositioncycle. The TiO₂ deposition cycle is repeated until a film of a desiredthickness is formed.

Although the illustrated TiO₂ deposition cycle begins with provision ofthe first Ti precursor, in other embodiments the deposition cycle beginswith the provision of the second reactant. It will be understood by theskilled artisan that provision of the first Ti precursor and secondreactant are interchangeable in the ALD cycle.

In some embodiments, the reactants and reaction by-products can beremoved from the substrate surface by stopping the flow of reactantwhile continuing the flow of an inert carrier gas such as nitrogen orargon. In some embodiments the reactants and reaction by-products can beremoved from the substrate surface by removing the substrate from thereaction chamber, or moving the substrate within the reaction chamber.

As mentioned above, in some embodiments a TiO₂ layer is selectivelydeposited on a first SiO₂ surface of a substrate relative to a secondH-terminated surface by a CVD process, such as a pulsed CVD process, inwhich a Ti precursor and an oxygen precursor are provided to thereaction chamber. In some embodiments a single Ti precursor is utilized.Thus, in some embodiments the process may not include contacting thesubstrate with a vapor phase second reactant. In some embodiments asubstrate is exposed to one precursor pulse, or sequential precursorpulses separate by a precursor removal or purge step. For example, insome embodiments a substrate may be continuously or intermittentlycontacted with a vapor phase Ti precursor and not with a vapor phasesecond reactant. Although in some embodiments a substrate may be contactby another species that does not react, such as an inert purge gas orcarrier gas, in addition to the vapor phase Ti precursor. In someembodiments a deposition process may include only one Ti precursorpulse. In some embodiments the substrate may be contacted with a vaporphase Ti precursor, excess Fe precursor and reaction byproducts, if any,may be removed from the substrate surface, and the substrate may againbe contacted with a vapor phase Ti precursor, for example in asequential pulse. In some embodiments the substrate may not contactedwith a second reactant. Although in some embodiments a substrate may becontacted by another species that does not react, such as an inert purgegas or carrier gas, in addition to the vapor phase Ti precursor.

Precursors

Suitable nickel precursors may be selected by the skilled artisan. Ingeneral, nickel compounds where the metal is bound or coordinated tooxygen, nitrogen, carbon or a combination thereof are preferred. In someembodiments a nickel precursor may be an organic compound. In someembodiments the nickel precursor is a metalorganic compound. In someembodiments the nickel precursor is a metal organic compound comprisingbidentate ligands. In some embodiments the nickel precursor isbis(4-N-ethylamino-3-penten-2-N-ethyliminato)nickel (ii).

In some embodiments, nickel precursors can be selected from the groupconsisting of nickel betadiketonate compounds, nickel betadiketiminatocompounds, nickel aminoalkoxide compounds, nickel amidinate compounds,nickel cyclopentadienyl compounds, nickel carbonyl compounds andcombinations thereof. In some embodiments, X(acac)_(y) or X(thd)_(y)compounds are used, where X is a metal, y is generally, but notnecessarily between 2 and 3 and thd is2,2,6,6-tetramethyl-3,5-heptanedionato. Some examples of suitablebetadiketiminato (e.g., Ni(pda)₂) compounds are mentioned in U.S. Pat.No. 9,103,019, the disclosure of which is incorporated herein in itsentirety. Some examples of suitable amidinate compounds (e.g.,Ni(^(i)Pr-AMD)₂) are mentioned in U.S. Pat. No. 7,557,229, thedisclosure of which is incorporated herein in its entirety.

The nickel precursor may also comprise one or more halide ligands. Inpreferred embodiments, the precursor is nickel betadiketiminatocompound, such bis(4-N-ethylamino-3-penten-2-N-ethyliminato)nickel (II)[Ni(EtN-EtN-pent)₂], nickel ketoiminate, suchbis(3Z)-4-nbutylamino-pent-3-en-2-one-nickel(II), nickel amidinatecompound, such as methylcyclopentadienyl-isopropylacetamidinate-nickel(II), nickel betadiketonato compound, such as Ni(acac)₂,Ni(thd)₂ ornickel cyclopentadienyl compounds, such Ni(cp)₂, Ni(Mecp)₂, Ni(Etcp)₂ orderivatives thereof, such asmethylcyclopentadienyl-isopropylacetamidinate-nickel (II). In morepreferred embodiment, the precursor isbis(4-N-ethylamino-3-penten-2-N-ethyliminato)nickel (II).

In some embodiments the first Ni precursor isbis(4-N-ethylamino-3-penten-2-N-ethyliminato)nickel (II).

Titanium precursors can be selected by the skilled artisan and can be,for example, titanium alkoxides (methoxide, ethoxide, isopropoxide), andtitanium alkylalmines.

Fe precursors can be selected by the skilled artisan. In someembodiments the Fe precursor is Cp₂Fe or a derivative thereof. In someembodiments the Fe precursor is Fe(acac)₂. In some embodiments the Feprecursor is Fe-alkoxide, such as iron(III) tert-butoxide(Fe₂(O^(t)Bu)₆). In some embodiments the Fe precursor is Fe(CO)₅. Insome embodiments the Fe precursor contains at least one cyclopentadienylligand (Cp), substituted cyclopentadienyl ligand or derivative thereof.In some embodiments the Fe precursor contains at least one carbonylligand (—CO) or derivative thereof. In some embodiments the Fe precursorcontains at least one carbonyl ligand (—CO) and at least one organicligand such as cyclopentadienyl ligand (Cp) or substitutedcyclopentadienyl ligand or derivative thereof.

Co precursors can be selected by the skilled artisan. In someembodiments the cobalt precursor may comprise a cobalt betadiketiminatocompound, cobalt ketoiminate compound, cobalt amidinate compound orcobalt betadiketonate compound.

In some embodiments the second precursor, or second reactant in an ALDprocess for forming elemental nickel is selected from hydrogen andforming gas. In other embodiments the second reactant may be an alcohol,such as EtOH.

In some embodiments the second reactant is an organic reducing agent.The organic reducing agents preferably have at least one functionalgroup selected from the group consisting of alcohol (—OH), as mentionedabove, or aldehyde (—CHO), or carboxylic acid (—COOH).

Reducing agents containing at least one alcohol group may be selectedfrom the group consisting of primary alcohols, secondary alcohols,tertiary alcohols, polyhydroxy alcohols, cyclic alcohols, aromaticalcohols, halogenated alcohols, and other derivatives of alcohols.

Preferred primary alcohols have an —OH group attached to a carbon atomwhich is bonded to another carbon atom, in particular primary alcoholsaccording to the general formula (I):R¹—OH  (I)wherein R¹ is a linear or branched C₁-C₂₀ alkyl or alkenyl groups,preferably methyl, ethyl, propyl, butyl, pentyl or hexyl. Examples ofpreferred primary alcohols include methanol, ethanol, propanol, butanol,2-methyl propanol and 2-methyl butanol.

Preferred secondary alcohols have an —OH group attached to a carbon atomthat is bonded to two other carbon atoms. In particular, preferredsecondary alcohols have the general formula (II):

wherein each R¹ is selected independently from the group of linear orbranched C₁-C₂₀ alkyl and alkenyl groups, preferably methyl, ethyl,propyl, butyl, pentyl or hexyl. Examples of preferred secondary alcoholsinclude 2-propanol and 2-butanol.

Preferred tertiary alcohols have an —OH group attached to a carbon atomthat is bonded to three other carbon atoms. In particular, preferredtertiary alcohols have the general formula (III):

wherein each R¹ is selected independently from the group of linear orbranched C₁-C₂₀ alkyl and alkenyl groups, preferably methyl, ethyl,propyl, butyl, pentyl or hexyl. An example of a preferred tertiaryalcohol is tert-butanol.

Preferred polyhydroxy alcohols, such as diols and triols, have primary,secondary and/or tertiary alcohol groups as described above. Examples ofpreferred polyhydroxy alcohol are ethylene glycol and glycerol.

Preferred cyclic alcohols have an —OH group attached to at least onecarbon atom which is part of a ring of 1 to 10, more preferably 5-6carbon atoms.

Preferred aromatic alcohols have at least one —OH group attached eitherto a benzene ring or to a carbon atom in a side chain. Examples ofpreferred aromatic alcohols include benzyl alcohol, o-, p- and m-cresoland resorcinol.

Preferred halogenated alcohols have the general formula (IV):CH_(n)X_(3-n)—R²—OH  (IV)

wherein X is selected from the group consisting of F, Cl, Br and I, n isan integer from 0 to 2 and R² is selected from the group of linear orbranched C₁-C₂₀ alkyl and alkenyl groups, preferably methyl, ethyl,propyl, butyl, pentyl or hexyl. More preferably X is selected from thegroup consisting of F and Cl and R² is selected from the groupconsisting of methyl and ethyl. An example of a preferred halogenatedalcohol is 2,2,2-trifluoroethanol.

Other derivatives of alcohols that may be used include amines, such asmethyl ethanolamine.

Preferred reducing agents containing at least one aldehyde group (—CHO)are selected from the group consisting of compounds having the generalformula (V), alkanedial compounds having the general formula (VI),halogenated aldehydes and other derivatives of aldehydes.

Thus, in some embodiments reducing agents are aldehydes having thegeneral formula (V):R³—CHO  (V)

wherein R³ is selected from the group consisting of hydrogen and linearor branched C₁-C₂₀ alkyl and alkenyl groups, preferably methyl, ethyl,propyl, butyl, pentyl or hexyl. More preferably, R³ is selected from thegroup consisting of methyl or ethyl. Examples of preferred compoundsaccording to formula (V) are formaldehyde, acetaldehyde andbutyraldehyde.

In other embodiments reducing agents are aldehydes having the generalformula (VI):OHC—R⁴—CHO  (VI)

wherein R⁴ is a linear or branched C₁-C₂₀ saturated or unsaturatedhydrocarbon. Alternatively, the aldehyde groups may be directly bondedto each other (R⁴ is null).

Reducing agents containing at least one —COOH group may be selected fromthe group consisting of compounds of the general formula (VII),polycarboxylic acids, halogenated carboxylic acids and other derivativesof carboxylic acids.

Thus, in some embodiment preferred reducing agents are carboxylic acidshaving the general formula (VII):R⁵—COOH  (VII)

wherein R⁵ is hydrogen or linear or branched C₁-C₂₀ alkyl or alkenylgroup, preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, morepreferably methyl or ethyl. Examples of preferred compounds according toformula (VII) are formic acid and acetic acid, most preferably formicacid (HCOOH).

In some embodiments a third reactant is used in the ALD cycle. In someembodiments, an ALD-type process for depositing Ni thin films comprisesalternate and sequential pulses of a nickel reactant, an organicreducing agent, and hydrogen or forming gas (such as 5% or 10% H₂ inN₂).

In embodiments in which titanium oxide is formed, exemplary oxygenreactants that may be used include, but are not limited to water, ozone,oxygen plasma, oxygen radicals or oxygen atoms.

In embodiments in which nickel nitride is formed, exemplary nitrogenreactants that may be used include NH₃. N-containing plasma,N/H-containing plasma.

EXAMPLES

The growth of Ni and Ni_(x)N_(y) was studied in both F-120 and Pulsar®2000 reactors. Two coupon substrates (5×5 cm2) were loaded in an F-120reactor simultaneously. The test was performed with a first substratecomprising a first SiO₂ surface and a second HF etched Si surface, and asecond substrate comprising an HF etched Si surface in the samedeposition run. The first substrate comprising a SiO₂ surface was maskedand etched with HF to form a first SiO₂ surface 710 and a secondH-terminated surface 720. The reaction temperature was set to 300° C.and Ni was grown by a pulsed CVD process as described herein, usingbis(4-N-ethylamino-3-penten-2-N-ehtyliminato nickel (II) as a Niprecursor. The CVD process included 1500 pulse and purge steps. Nosecond reactant was pulsed into the reaction chamber. As illustrated inFIG. 7, nickel was selectively deposited on the first SiO₂ surface 710of the first substrate relative to the second HF etched (Si—H) surface720. No nickel was deposited on the second substrate comprising an HFetched Si surface. Thus, the deposition temperature was high enough toobtain Ni precursor decomposition on an Si—OH terminated surface, forexample surface 710, but not on Si—H terminated surface such as surface720.

A test was also performed in a Pulsar® 2000 reactor, and deposition wascarried out according to a process as described herein by pulsing anickel precursor and a NH₃ second reactant 4000 times at a temperatureof 300° C. No film was observed on the HF etched 200 mm Si wafer, whilea Ni_(x)N_(y) film was deposited on a first surface comprising SiO₂ of a200 mm wafer relative to a second surface comprising Si.

Another test was also performed in a Pulsar® 2000 reactor, anddeposition was carried out usingbis(4-N-ethylamino-3-penten-2-N-ehtyliminato)nickel (II) as a Niprecursor. The CVD process included 5000 pulses, with a duration ofabout is each, and purges, with a duration of about 5 s each, atreaction temperature of 300° C. Nickel was selectively deposited on thefirst SiO₂ surface of the first substrate relative to the second HFetched (Si—H) surface of the second substrate. XPS analysis confirmedthe deposition of nickel on the SiO₂ surface. No nickel was deposited onthe second substrate comprising an HF etched Si surface. Thus, thedeposition temperature was high enough to obtain Ni precursordecomposition on, for example, an Si—OH terminated surface, but not on,for example, a Si—H terminated surface.

Selective Growth of SiO₂ on Si—H Relative to SiO₂

The selective deposition of a material comprising Ni, Ti, Fe, or Co,such as nickel, nickel nitride or titanium oxide on a SiO₂ surfacerelative to an H-terminated surface, such as an SiH₃, —SiH₂, or SiHsurface, allows for the selective growth of SiO₂ on the H-terminatedsurface. In some embodiments following selective deposition of amaterial comprising Ni, Ti, Fe, or Co on a first surface as describedherein, such as a SiO₂ surface, relative to a second H-terminatedsurface, as described herein, SiO₂ can subsequently be selectivelydeposited on the second H-terminated surface (such as a SiH₃, —SiH₂, orSiH surface) relative to the first surface, for example a Ni, NiN_(x),Fe or Co or titanium oxide surface. Deposition of the SiO₂ may be by anymethod known in the art, such as by PEALD using oxygen radicals, plasmaor atomic oxygen, or by thermal ALD using, for example ozone. In someembodiments both thermal and plasma ALD processes are employed. Siliconprecursors that are known in the art may be used. In some embodiments asilicon precursor may comprise (R^(I)R^(II)N)₂SiH₂, X_(y)SiH_(4-y),(R^(I)R^(II)N)_(y)SiH_(4-y), or (R^(I)R^(II)N)SiH₃, where R^(I) andR^(II) are preferably independently selected from C₁-C₅ alkyls, such asmethyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and X can be, forexample, a halide. In some embodiments the SiO₂ is formed by exposingthe substrate to oxygen plasma.

Following selective growth of the SiO₂ of a desired thickness on thesecond surface relative to the first surface, the a material comprisingNi, Ti, Fe, or Co that was previously deposited on the first surface canbe removed, such as by etching. The etch process preferably leaves thenewly formed SiO₂ layer on the second surface intact. By blocking thefirst SiO₂ surface with a material comprising Ni, Ti, Fe, or Co,selective formation of SiO₂ on the H-terminated surface (such as a SiH,—SiH₂, or SiH₃ surface) relative to the blocked SiO₂ surface ispossible.

In some embodiments the etch step comprises exposing the substrate to aselective metal etch (e.g., HCl, or piranha (H₂SO₄:H₂O₂) dip). Forexample, the substrate may be dipped in dilute aqueous HCl and/or HNO₃or piranha etch, which can etch most metals, including nickel, withoutappreciable attack of silicon, silicon oxide or other non-metalmaterials used in integrated circuit manufacture.

We claim:
 1. A deposition method comprising: providing a substratecomprising a first surface and a second, chemically different surface,wherein the first surface comprises at least one AH_(x) termination,where A is one or more of N, O, or S and x is from 1 to 2, and thesecond surface comprises Si—H_(X) terminations surface, where x is from1 to 3; and contacting the first surface and the second surface of thesubstrate with a first vapor phase precursor comprising Ni, Ti, Fe, orCo; thereby selectively depositing a material comprising Ni, Ti, Fe, orCo on the first surface of the substrate relative to the second surfaceof the same substrate.
 2. The method of claim 1, wherein the selectivelydeposited material comprises Ni or Co.
 3. The method of claim 1, whereinselectively depositing further comprises contacting the substrate with asecond vapor phase reactant.
 4. The method of claim 1, wherein thesecond surface comprising Si—H_(x) terminations is formed by treating atleast a portion of the substrate surface prior to depositing thematerial.
 5. The method of claim 1, wherein the second surfacecomprising Si—H_(x) terminations is formed by treating at least aportion of the substrate surface with a HF etch.
 6. The method of claim1, wherein the second surface comprising Si—H_(x) terminations is formedby treating at least a portion of the substrate surface with a siliconcompound comprising ClSiH₃ or (R^(I)R^(II)N)SiH₃, where R^(I) and R^(II)are independently selected from C₁-C₄ alkyls, such as methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl.
 7. The method of claim 1, whereinthe first surface comprises at least one OH-termination.
 8. The methodof claim 1, wherein the first surface comprises SiO₂.
 9. The method ofclaim 1, wherein the first surface is a low-k insulator.
 10. The methodof claim 1, wherein the first surface comprises silicon oxide, siliconnitride, silicon oxynitride, fluorinated silica glass, carbon dopedsilicon oxide, or another material comprising at least 50% siliconoxide.
 11. The method of claim 1, wherein the material comprising Ni,Ti, Fe, or Co is selectively deposited on the first surface relative tothe second surface comprising Si—H_(x) terminations with a selectivityof at least 90%.
 12. The method of claim 1, further comprising etchingthe substrate to remove any material comprising Ni, Ti, Fe, or Co fromthe second H-terminated silicon surface of the substrate.
 13. The methodof claim 1, wherein the deposition method is an ALD or CVD process. 14.The method of claim 13, wherein the selective deposition process is anALD process.
 15. A method of selectively depositing a materialcomprising Ni, Ti, Fe, or Co on a substrate, the method comprising:providing a substrate comprising a first surface comprising siliconoxide; etching at least a portion of the first surface to therebyprovide a second H-terminated silicon surface; and selectivelydepositing a material comprising Ni, Ti, Fe, or Co on the first surfacecomprising silicon oxide relative to the second H-terminated siliconsurface.
 16. The method of claim 15, wherein the method of selectivelydepositing a material comprising Ni, TI, Fe, or Co on a substrate is anALD or CVD process.
 17. The method of claim 15, wherein etching at leasta portion of the first surface comprises exposing said portion of thefirst surface to HF.
 18. The method of claim 15, wherein the materialcomprising Ni, Ti, Fe, or Co film is selectively deposited on the firstsurface relative to the second H-terminated silicon surface with aselectivity of at least 90%.
 19. A method for selectively forming SiO₂on a substrate comprising: selectively depositing material comprisingNi, Ti, Fe, or Co on a first surface of the substrate relative to asecond H-terminated silicon surface of the same substrate, wherein thefirst surface comprises at least an AH_(x) termination, where A is oneor more of O, N and S and x is from 1 to 2; selectively depositing SiO₂on the second H-terminated silicon surface of the substrate relative tothe first surface of the same substrate.
 20. The method of claim 19,wherein the first surface comprises an OH-terminated surface.
 21. Themethod of claim 19, wherein the first surface comprises silicon oxide.22. The method of claim 19, wherein the second H-terminated siliconsurface comprises —SiH, —SiH₂, or —SiH₃ surface terminations.
 23. Themethod of claim 19, wherein SiO₂ is selectively deposited on the secondH-terminated silicon surface of the substrate relative to the firstsurface by a PEALD or thermal ALD process.
 24. The method of claim 19,wherein the method further comprises etching the substrate to remove thematerial comprising Ni, Ti, Fe, or Co from the substrate.
 25. The methodof claim 24, wherein etching the substrate comprises exposing thesubstrate to at least one of HCl, HNO₃, or H₂SO₄:H₂O₂.